1. Field of the Invention
The present invention relates to a method, a device and a computer program for mapping a moving direction by using sounds.
2. Description of Related Art
In recent years, numerous systems have been developed for assisting people with visual impairments to engage in activities and process information in ways comparable to those without visual impairments. For example, there are systems capable of estimating the direction in which a person with a visual impairment is moving, on the basis of information which the person with the visual impairment acquires by use of a sense other than sight, e.g. a sense of hearing, smelling, touch or the like.
A number of techniques have already been disclosed for techniques of indicating a traveling direction, navigational techniques and the like. For example, the navigation apparatus shown in U.S. Pat. No. 7,620,493 generates a movement instruction regarding a distance and a direction to move from a current position to a target position, on the basis of information on the surrounding environment, e.g. information acquired by use of the sense of hearing, smelling, touch or the like.
Moreover, techniques for identifying a direction and a distance by using sounds have also been proposed. For example, in Tooba Nasir, Jonathan C. Roberts, “Sonification of spatial data”, the 13th International Conference on Auditory Display, Montreal (Canada), Jun. 26-29, 2007, accurate positional information can be informed even to a person with visual impairment by use of stereo effects using two or more sound sources. The use of sounds is considered especially effective in guiding a person with visual impairment towards a dynamically changing direction.
Even though guiding a person with visual impairment by using sound is effective, the conventional techniques can express directions only one-dimensionally, thus, having difficulty in producing sound indicating a desired direction. For example, in the case of providing movement instructions by uttering meaningful words, the words each indicating a one-dimensional direction are repeated intermittently. Specifically, to provide an instruction to move forward to the right at a 45-degree angle, the words of “right” and “forward” are repeated as “right, forward, right, forward . . . . ” Accordingly, it is too complicated to provide an instruction of a detailed direction, and is too difficult for people with visual impairments to correctly catch a movement instruction if the instruction is overlapped with another sound.
Although accurate positional information can be informed by using stereo effects, this technique requires a large-scale system with the necessity of preparing two or more sound sources, and hence has a problem that it is difficult to reduce the total cost for system construction.